Bridged-ring nomenclature

Bridged-ring nomenclature uses a prefix, suffix, and bracket term as in bicyclo[4.3.2]undecane (Figure 6.37). The prefix indicates the number of bridging rings (bicycle, tricycle, etc.) and whether those rings include any heteroatoms (oxa. thia, aza, etc.). 

Schmerling, L., "Nomenclature of Aliphatic, Alicyclic, and Bridged Ring Compounds, ... 

A bridged-ring system is one in which two alicyclic rings have two or more atoms in common. These atoms bridge-head atoms) do not have to be adjacent to one another. Such compounds have a unique numbering pattern and nomenclature. 

Symmetrical diaLkyl peroxides are commonly named as such, eg, dimethyl peroxide. For unsymmetrical diaLkyl peroxides, the two radicals usually are hsted ia alphabetical order, eg, ethyl methyl peroxide. For organomineral peroxides or complex stmctures, ie, where R and R are difficult to name as radicals, the peroxide is named as an aLkyldioxy derivative, although alkylperoxy is stUl used by many authors. CycHc peroxides are normally named as heterocychc compounds, eg, 1,2-dioxane, or by substitutive oxa nomenclature, eg, 1,2-dioxacyclohexane however, when the two oxygens form a bridge between two carbon atoms of a ring, the terms epidioxy or epiperoxy are frequendy used. The resulting polycycHc stmcture has been called an endoperoxide, epiperoxide, or transaimular peroxide. 

The alcohol portion in hyoscyamine is tropine in hyoscine it is the epoxide scopine. Tropine is an example of an azabicyclo[3,2,l]octane system with a nitrogen bridge, whereas scopine is a tricylic system with a three-membered epoxide ring fused onto tropine. Note that systematic nomenclature considers an all-carbon ring system with one carbon replaced by nitrogen hence, tropane is an azabicyclooctane (see Section 1.4). 

Polycyclic parent hydrides. These are classified as bridged polyalkanes (also known as von Baeyer bridged systems, from the nomenclature system developed to name them), spiro compounds, fused polycyclic systems and assemblies of identical rings. The four systems may be either carbocyclic or heterocyclic. In developing their names, the following principles are used. 

The nomenclature of phanes is simple 32) It mainly defines the length(s) of the bridge(s) and their positions in the ring as illustrated by the following examples [6]para-cyclophane (2) 1,10-dioxa [10]paracyclophane (6), [2.2]paracyclophane (7), [2.2]meta-(8) and [2.2]metaparacyclophane (9) and [8](2,5)pyridinophane (70). The formulae show also the kind of projection used in this survey to illustrate stereochemical relations. 

For this review, heterophanes are considered to contain one or more heteroaromatic ring(s) bridged by a non-aromatic chain of atoms. Although a certain arbitrariness identifies (1) but not (2), as a heterophane, this definition focuses attention on the chemistry appropriate for this review and makes the volume of literature to be reviewed more manageable. Different nomenclature approaches for heterophanes have been proposed (70T5847,72T5183, 72TL2109) as alternatives for the currently accepted, complex IUPAC or Chemical Abstracts names, which actually obscure the phane structural element in these compounds. A proposal... 

Polynuclear inorganic compounds exist in a bewildering array of structural types, such as ionic solids, molecular polymers, extended assemblies of oxounions both of metals and nonmeinis, nonmetal chains and rings, bridged melui complexes, and homo- and hetero-nuclcar clusters. This section treats primarily the nomenclature of bridged metal complexes and homo- and hetero-nuclear dusters. 

Bridging nomenclature should not be used when addition of the bridge is equivalent to adding a further fused ring, e.g., 42 is named 1,2,3,4-tetrahydrobenzo[a]phenazine, not 1,2-butanophenazine. 

Figure F4.1.1 Structural differences between major classes of natural chlorophylls in higher plants and algae. Designation of pyrrole rings A-D and methene bridges a-5 is based on the nomenclature outlined by Fisher and Orth (1937).

Resveratrol is a member of the stilbene family, a group of compounds which consist of two aromatic rings joined by a methylene bridge. 3,4, 5-trihydrox-ystilbene is the IUPAC (International Union of Pure and Applied Chemistry) nomenclature for resveratrol but is also known as 3,4, 5-stilbenetriol, and it has... 

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